Journal of thermal biology最新文献

{"title":"Effect of exposure to extreme temperatures on fertility of males of the eurythermic lizard Barisia imbricata","authors":"Alejandro Cadena-Velázquez,&nbsp;Edith Arenas-Ríos,&nbsp;Andrés García Aguayo,&nbsp;Ahiezer Rodríguez-Tobón,&nbsp;Norma L. Manríquez-Morán,&nbsp;Fausto R. Méndez-de la Cruz","doi":"10.1016/j.jtherbio.2026.104548","DOIUrl":"10.1016/j.jtherbio.2026.104548","url":null,"abstract":"<div><div>Extreme temperatures can compromise reproduction in viviparous reptiles. We evaluated whether thermal stress affects male reproductive traits in <em>Barisia imbricata</em>, a eurythermic and cryophilic high-elevation lizard. Males were exposed for 12 h per day during 7 days to low (10 °C) or high (35 °C) temperatures, and testicular histology, gonadosomatic and epididymosomatic indices, circulating testosterone concentrations, and sperm performance were assessed. Sperm progressive motility was additionally evaluated over a 12-h incubation period at five temperatures (5, 10, 26, 35, and 38 °C). Both low and high treatments reduced gonadosomatic and epididymosomatic indices. Histological analyses revealed largely preserved seminiferous tubule organization, with mild epithelial alterations at low temperature and greater disorganization at high temperature, but without complete structural damage. Testosterone concentrations decreased under low-temperature exposure but remained similar to controls at high temperature. Sperm progressive motility remained detectable throughout the 12-h experimental period at low temperatures (5 to 10 °C), whereas exposure to warmer temperatures (26 to 38 °C) caused a rapid decline in sperm motility, with complete immobility occurring fastest at 38 °C. These results indicate that <em>B. imbricata</em> shows considerable reproductive tolerance to thermal extremes, although warmer temperatures constrain sperm performance. Our findings partially support the proposed hypothesis by demonstrating that short-term thermal sensitivity varies among reproductive traits, with testicular structure remaining largely preserved despite mild histological alterations, whereas sperm performance showed greater vulnerability to warming. These findings highlight the importance of reproductive thermal physiology in understanding reptile vulnerability under climate warming.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"140 ","pages":"Article 104548"},"PeriodicalIF":3.2,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148813359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"General patterns and predictors of thermal tolerance in bees: A global synthesis across taxa and environments","authors":"Fernanda Baena-Díaz,&nbsp;Misael Morales-Gómez,&nbsp;Brenda Ratoni,&nbsp;Victor Hugo Gonzalez,&nbsp;Wesley Dáttilo","doi":"10.1016/j.jtherbio.2026.104538","DOIUrl":"10.1016/j.jtherbio.2026.104538","url":null,"abstract":"<div><div>Understanding how organisms respond to temperature variation has become central to ecology and evolution because of its role in shaping species' physiology, distribution, and ecological interactions. Thermal tolerances are critical for ectothermic organisms, which have evolved a variety of behavioral and physiological strategies to manage thermal stress that vary widely across geographic and temporal scales. This study synthesizes existing information on bees' critical thermal maximum (CT_max) and minimum (CT_min) through a systematic review of published data. Despite bees' ecological importance, research on such common metrics of thermal tolerance remains scarce, with fewer than 50 accumulated studies over the past 30 years and less than 1% of species represented. Data are biased to North America, especially the USA, Oceania and Europe, leaving vast regions unexplored. We found that while CT_max correlated with variables related to body size and ramping rates during measurement but no with mean, maximum and minimum temperatures; CT_min only correlate with the coldest month's minimum temperature and mean annual temperature. These patterns underscore the role of local climate in shaping thermal adaptation. However, major knowledge gaps persist, limiting predictions of climate change impacts. We call for broader studies on intra-specific thermal tolerance variation across geography, life stages, and social traits to predict climate change impacts and guide bee conservation.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"140 ","pages":"Article 104538"},"PeriodicalIF":3.2,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148536315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermoregulatory accuracy in Liolaemus lutzae: do sex and age influence thermoregulatory effectiveness?","authors":"Paulo Nogueira-Costa,&nbsp;Patricia Almeida-Santos,&nbsp;Catia Moura Militão,&nbsp;Vanderlaine Amaral Menezes,&nbsp;Barry Sinervo,&nbsp;Donald Miles,&nbsp;Carlos Frederico Duarte Rocha","doi":"10.1016/j.jtherbio.2026.104547","DOIUrl":"10.1016/j.jtherbio.2026.104547","url":null,"abstract":"<div><div>We investigated aspects of the thermal niche of the liolaemid lizard <em>Liolaemus lutzae</em>, aiming to compare thermoregulatory accuracy between sexes and between juveniles and adults. We sampled body temperatures and operative environmental temperatures across a range of microhabitats potentially used by <em>L. lutzae</em>. Preferred body temperatures and the set-point range of individuals were estimated in a laboratory photothermal gradient. We estimated three thermoregulation indices to evaluate the efficiency of thermoregulation and compared the thermoregulatory accuracy of different sexes and ages. The accuracy of <em>T</em>_<em>b</em> was calculated using the mean of the deviations of <em>T</em>_<em>b</em> from <em>T</em>_<em>set</em> (<span><math><mrow><msub><mover><mi>d</mi><mo>‾</mo></mover><mi>b</mi></msub></mrow></math></span>), the thermal quality of each microhabitat was assessed measuring the mean of the deviations of <em>T</em>_<em>e</em> from <em>T</em>_<em>set</em> (<span><math><mrow><msub><mover><mi>d</mi><mo>‾</mo></mover><mi>e</mi></msub></mrow></math></span>), and the effectiveness of thermoregulation (<em>E</em>) calculated from the formula <span><math><mrow><mi>E</mi><mo>=</mo><mn>1</mn><mo>−</mo><msub><mover><mi>d</mi><mo>‾</mo></mover><mi>b</mi></msub><mo>/</mo><msub><mover><mi>d</mi><mo>‾</mo></mover><mi>e</mi></msub></mrow></math></span>. We found a difference between <span><math><mrow><msub><mover><mi>d</mi><mo>‾</mo></mover><mi>b</mi></msub></mrow></math></span> of adults and juveniles but not between males and females. The juveniles had higher values of <em>E</em> compared to adults of both sexes. We observed negative values of <em>E</em> between 8h00 and 9h00 and after 15h00. The period between 11h00 and 13h00 showed values of <em>E</em> closest to 1 for both, juveniles and adults. <em>Liolaemus lutzae</em> is usually exposed to temperatures above its preferred range in the study area, especially between 10:00 and 15:00 (60% of its activity period), when the average operative temperature (<em>T</em>_<em>e</em>) exceeds the <em>T</em>_<em>set</em>. The lizards were exposed to extreme temperatures between 11:00 and 14:00 when the <em>T</em>_<em>e</em> exceeds the <em>CT</em>_<em>max</em>. The thermal quality of microhabitats tended to vary throughout the day, requiring <em>L. lutzae</em> to actively thermoregulate. Juvenile <em>L. lutzae</em> seemed to thermoregulate more accurately than adults. Juveniles compensate for their lower thermal inertia through careful behavioral thermoregulation, which explains the absence of differences in body temperature (<em>T</em>_<em>b</em>) between adults and juveniles.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"140 ","pages":"Article 104547"},"PeriodicalIF":3.2,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148844195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal sensitivity and aerobic scope in paralarvae of Octopus tetricus","authors":"Jeffrey Good,&nbsp;Andrew Jeffs,&nbsp;Quinn Fitzgibbon,&nbsp;Stefan Spreitzenbarth","doi":"10.1016/j.jtherbio.2026.104561","DOIUrl":"10.1016/j.jtherbio.2026.104561","url":null,"abstract":"<div><div>Temperature strongly influences metabolic performance and survival during the early life stages of cephalopods, yet the thermal requirements of octopus paralarvae remain poorly defined. This study examined the effects of temperature on metabolic rates and aerobic scope of gloomy octopus (<em>Octopus tetricus</em>) paralarvae to identify an optimal rearing temperature during the first four days post-hatch. Oxygen consumption was quantified using closed-system respirometry at six temperatures (12, 15, 18, 21, 24, and 27 °C) in paralarvae aged 0, 2, and 4 days post-hatch. Standard (SMR), routine (RMR), and maximum metabolic rates (MMR) were measured, and used to calculate aerobic scope (AS). Metabolic rates varied significantly with temperature, with both low and high thermal extremes depressing performance. AS exhibited a clear temperature-dependent parabolic pattern, peaking at 3.34 mg O₂ gDW⁻¹ h⁻¹. Quadratic modelling identified an optimal temperature (<em>T</em>_opt) of 18.98 °C. Behavioural observations aligned with physiological trends as paralarvae at cooler temperatures showed reduced activity and delayed exhaustion, whereas elevated temperatures increased metabolic demand and reduced aerobic capacity. Temperature-dependent Q₁₀ analyses revealed exceptionally high thermal sensitivity immediately post-hatch, which moderated rapidly by 4 dph, indicating strong early developmental constraints and a narrowing of physiological vulnerability with age. These findings indicate that rearing <em>O. tetricus</em> paralarvae at ∼19 °C maximizes aerobic performance during a critical developmental window when individuals transition from yolk utilisation to active predation. This study provides the first empirically derived <em>T</em>_opt for any octopus paralarva and establishes a physiological basis for refining aquaculture protocols while informing predictions of early-life sensitivity to ocean warming.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"140 ","pages":"Article 104561"},"PeriodicalIF":3.2,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148770845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonal heat stress alters rumen fermentation, microbial community, and microbial amino acid composition in cattle","authors":"Yong Ho Jo,&nbsp;Won Seob Kim,&nbsp;Yoo Rae Kim,&nbsp;Moon Su Ju,&nbsp;Jalil Ghassemi Nejad,&nbsp;Kyoung Hoon Kim,&nbsp;Hong Gu Lee","doi":"10.1016/j.jtherbio.2026.104509","DOIUrl":"10.1016/j.jtherbio.2026.104509","url":null,"abstract":"<div><div>In this study, we investigated the effects of seasonal changes on ruminal temperature, pH, fermentation characteristics, microbial composition, and microbial amino acids (AAs) in cattle.</div><div>The experiment was conducted using six fistulated Holstein steers in two separate 9-d trials conducted in spring and summer (3 d adaptation and 6 d sampling). The average ambient temperature and relative humidity were 10.7 °C and 58% in spring and 24.5 °C and 83.5% in summer, respectively. Ruminal temperature was approximately 0.9 °C higher in summer than in spring, whereas ruminal pH was 0.15 units lower in summer. Among rumen fermentation parameters, butyrate concentration increased during summer, while the concentrations of acetate, propionate, branched-chain fatty acids, total volatile fatty acids, and NH₃-N decreased (<em>p</em> &lt; 0.05). Despite identical feed intake, ruminal degradation rates increased after 24 h in summer, with significant increases in the degradation of dry matter, crude protein, and neutral detergent fiber (<em>p</em> &lt; 0.05). Microbial community analysis revealed that at the phylum level, <em>Spirochaetota</em> decreased, whereas <em>Planctomycetota</em> and <em>Chloroflexi</em> increased during summer (<em>p</em> &lt; 0.05). At the genus level, <em>Succiniclasticum</em> and <em>Treponema</em> decreased, while <em>Eubacterium coprostanoligenes</em> and <em>Oscillospiraceae</em> increased compared with spring (<em>p</em> &lt; 0.05). Changes in microbial composition were accompanied by alterations in microbial AA profiles, characterized by increases in alanine, glutamate, histidine, and non-essential AAs, and decreases in glycine, serine, methionine, threonine, and essential AAs during summer (<em>p</em> &lt; 0.05). Notably, methionine content decreased by 13% in summer relative to spring. Overall, these findings demonstrate that seasonal thermal conditions directly alter rumen fermentation, microbial ecology, and microbial AA composition, even under identical feeding conditions. This study provides foundational evidence for developing nutritional and management strategies to optimize rumen function under heat stress conditions.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"139 ","pages":"Article 104509"},"PeriodicalIF":3.2,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148283700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Blood parasite infection is associated with lower thermoregulatory precision in the lizard Podarcis lusitanicus","authors":"J. Filipe Faria,&nbsp;Rodrigo Megía-Palma,&nbsp;Martin J. Whiting,&nbsp;D. James Harris","doi":"10.1016/j.jtherbio.2026.104514","DOIUrl":"10.1016/j.jtherbio.2026.104514","url":null,"abstract":"<div><div>Parasites have the potential to disrupt and induce changes in thermoregulation and behaviour in ectotherm hosts, possibly with deleterious effects. In a previous study, the lizard <em>Podarcis lusitanicus</em> (Lacertidae), when infected with blood parasites of the genus <em>Karyolysus</em> (suborder Adeleorina), were bolder, remained exposed for longer, and tended to explore more. To determine if this behaviour was linked to the lizards’ thermoregulatory behaviour, we recorded the temperatures of male lizards with varying blood parasite infection levels in a thermal gradient during their active diurnal period. Infected lizards had lower thermoregulatory precision, indicating an association with the previously observed higher exploratory behaviour of infected individuals. However, parasite infection was not significantly associated with higher median or maximum recorded body temperatures, suggesting that the lizards were not compensating through behavioural fever. While we observed no significant effect on leucocyte counts from the parasite infection or thermal variables, the latter had a different magnitude of effect on the host cellular immune response depending on whether the lizard was parasitised or not. The cellular immune response of parasitised lizards increased less with increasing thermal variables (preferred body temperature, maximum recorded temperature, and thermoregulatory precision), suggesting the parasite infection might be negatively affecting the development of stronger immune responses in these hosts. It is also possible that changes to host thermoregulation and behaviour might benefit the parasite beyond its infectious stage in the intermediate vertebrate host, because increasing exploratory behaviour in the lizard could increase the probability of contact with haematophagous mites, the definitive hosts of <em>Karyolysus</em> sp. Finally, while tail condition was not significantly related to thermal preference, lizards with regenerated tails had significantly higher thermoregulation precision than lizards with original tails, highlighting the need for additional studies on the real impact of tail autotomy and regeneration in thermoregulatory capabilities of lizards.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"139 ","pages":"Article 104514"},"PeriodicalIF":3.2,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148295551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heat-related increase in Kawasaki disease risk with delayed effects: Evidence from time-series and case-crossover analyses in Seoul, South Korea","authors":"Kiook Baek,&nbsp;Jung Hee Hong","doi":"10.1016/j.jtherbio.2026.104508","DOIUrl":"10.1016/j.jtherbio.2026.104508","url":null,"abstract":"<div><h3>Background</h3><div>This study examined the association between ambient temperature and Kawasaki disease (KD) incidence, emphasizing delayed effects and age-specific susceptibility using nationwide data from Seoul, Korea.</div></div><div><h3>Methods</h3><div>KD cases treated with intravenous immunoglobulin among children aged 0–9 years in Seoul (2012–2019) were identified from the HIRA database and coded daily. Associations between mean temperature and KD were analyzed using a time-stratified case-crossover design and quasi-Poisson time-series regression within a distributed lag non-linear model (up to 21 lag days).</div></div><div><h3>Results</h3><div>In the case-crossover analysis, KD risk increased linearly above 25 °C at a cumulative lag of 14–21 days, with an odds ratio (OR) of 1.13 (95% CI: 1.03–1.23) at 29.7 °C (97.5th percentile) versus 25 °C. The time-series model showed similar results, with a relative risk (RR) of 1.14 (95% CI: 1.05–1.25) at 29.7 °C. No significant decrease was observed at low temperatures (−6.9 °C). Age-stratified analyses revealed the strongest associations among children aged 1–4 years.</div></div><div><h3>Conclusions</h3><div>High ambient temperature was associated with a delayed increase in KD incidence, particularly among children aged 1–4 years. These findings suggest that heat exposure may play a role in KD pathogenesis, potentially through effects on infection susceptibility and host immune responses.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"139 ","pages":"Article 104508"},"PeriodicalIF":3.2,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148271982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal manipulation during mid-embryogenesis alters myogenic gene expression and muscle morphometry in broilers","authors":"Henrique C. Lobato,&nbsp;Otoniel F. Souza,&nbsp;Mariana C. Vieira,&nbsp;Laryssa F. Bernardes,&nbsp;Victor F. Araújo,&nbsp;Clayton B. Galvão,&nbsp;Artur F. Ribeiro,&nbsp;Cristhian D.A. Alfaro,&nbsp;Kirsty X.N. Carrasco,&nbsp;Érika C. Jorge,&nbsp;Márcio G. Zangerônimo,&nbsp;Marcos H. Soares,&nbsp;Henry van den Brand,&nbsp;Leonardo J.C. Lara,&nbsp;Itallo C.S. Araújo","doi":"10.1016/j.jtherbio.2026.104502","DOIUrl":"10.1016/j.jtherbio.2026.104502","url":null,"abstract":"<div><div>This study evaluated the effects of embryonic thermal manipulation (TM) at 39.5°C and 40.5°C for 6 or 12 h daily, from days 7 to 16 of embryonic development (ED), on hatchability, embryo mortality, hatching pattern, chick quality, yolk sac weight, breast muscle gene expression of Heat Shock Protein 70 (HSP70), Myogenic Differentiation 1 (MYOD), Type II Iodothyronine Deiodinase (DIO2), serum hormones and breast muscle histomorphometry at pulling. A total of 4300 hatching eggs from a 39-week-old Ross 308 breeder flock were used. Eggs were randomly assigned to five treatments (860 eggs each) in a completely randomized design: a control treatment (37.5°C and 60% relative humidity (RH) until 18 ED) and four TM protocols applied daily: 39.5°C/6h, 39.5°C/12h, 40.5°C/6h, and 40.5°C/12h, all with 65% RH. The 40.5°C/12h treatment showed the lowest hatchability (31.55%) and Tona chick quality score (75.30) (P &lt; 0.05). Mid-term embryonic mortality was higher in the 40.5°C/12h treatment (18.77%) compared with other treatments (P &lt; 0.05), while late mortality was higher in the 40.5°C/6h (12.30%) and 40.5°C/12h (43.55%) treatments compared with other treatments (P &lt; 0.05). Yolk sac relative weight at hatch was higher in the 40.5°C/12h treatment (15.85%) than in other treatments (P &lt; 0.05). HSP70 gene expression in breast muscle post-hatch was markedly upregulated in 40.5°C/12h (fold change = 380.38) compared with control (1.0), 39.5°C/6h (1.33), 39.5°C/12h (1.13), and 40.5°C/6h (0.7) (P &lt; 0.05). Conversely, MYOD expression was suppressed in all TM treatments (fold change = 0.03, 0.02, 0.03, and 0.03) compared with control (1.00; P &lt; 0.05). At pulling, myocyte area was greater in the 39.5°C/6h (22.23 μm²) and 40.5°C/6h (21.84 μm²) treatments compared with control (21.14 μm²), 39.5°C/12h (19.61 μm²), and 40.5°C/12h (20.26 μm²; P &lt; 0.05). In conclusion, embryonic TM under the 39.5°C/6h program showed potential benefits for early muscle development by downregulating MYOD and increasing myocyte area at pulling, without impairing hatchability or day-old chick quality.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"139 ","pages":"Article 104502"},"PeriodicalIF":3.2,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148252053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal environments drive the metabolomic response of an intertidal snail at microhabitat scale","authors":"Ning Zhang,&nbsp;Yun-Wei Dong","doi":"10.1016/j.jtherbio.2026.104511","DOIUrl":"10.1016/j.jtherbio.2026.104511","url":null,"abstract":"<div><div>Extreme high-temperature events pose severe physiological challenges to species, with conspecific individuals experiencing divergent thermal stress across heterogeneous microhabitats. Investigating metabolomic response patterns provides critical insights into how these organisms respond to extreme heat at the microhabitat scale. In the present study, we conducted in situ measurements of substrate and body temperatures to analyze the relative importance of substrate temperature to body temperature. Additionally, we determined the metabolomic responses of intertidal snails <em>Littorina brevicula</em> inhabiting exposed and shaded rock microhabitats during an extreme high-temperature event in summer. Results showed that microhabitat type and substrate temperature significantly affect the body temperatures of intertidal snails. Snails inhabiting different microhabitats exhibited distinct metabolomic response patterns. On exposed rock, snails showed a metabolomic response pattern of high-energy expenditure, strong defense, and robust repair, while snails on shaded rock preferred to maintain cellular homeostasis. Variations in temperature across different microhabitats can alter the functional priorities of the snails' metabolic networks and can lead to functional differentiation in the same metabolic pathways depending on the microhabitat. These findings underscore the importance of microhabitat thermal heterogeneity and enhance our understanding of metabolomic responses to thermal stress at the microhabitat level.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"139 ","pages":"Article 104511"},"PeriodicalIF":3.2,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148258483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diapause- and cold-induced remodeling of phospholipid composition in the biological membranes of the boreal fly, Drosophila lummei","authors":"Panalee Petcharat,&nbsp;Petra Berková,&nbsp;Petr Vodrážka,&nbsp;Martin Moos,&nbsp;Vladimír Košťál","doi":"10.1016/j.jtherbio.2026.104519","DOIUrl":"10.1016/j.jtherbio.2026.104519","url":null,"abstract":"<div><div>The theory of homeoviscous adaptation (HVA) predicts that poikilothermic animals exposed to decreasing ambient temperatures maintain optimal phospholipid bilayer fluidity by increasing the proportion of phosphatidylethanolamines (PEs) relative to phosphatidylcholines (PCs) and/or unsaturated fatty acyls (UFAs) relative to saturated fatty acyls (SFAs). These predictions have been tested in numerous insect species, including the genetically tractable model <em>Drosophila melanogaster</em>. However, <em>D. melanogaster</em>, a warm-adapted species of tropical origin, exhibits relatively minor cold-induced changes in its phospholipidome. Here, we investigated the boreal, cold-adapted fly <em>D. lummei</em> and observed substantial membrane lipid remodeling during winter diapause and gradual cold acclimation, largely consistent with HVA predictions. Phospholipid classes and fatty acyl profiles were broadly similar across whole body, flight muscle tissue, and flight muscle-derived mitochondria, yet differed in detail and responded specifically to acclimation. The PE/PC ratio increased during cold acclimation in whole body and mitochondria, but not in flight muscles, and correlated only weakly with cold tolerance. In contrast, the UFA/SFA ratio increased markedly in all sample types and closely tracked improvements in cold tolerance. This increase occurred in two phases: an early rise in monounsaturated FAs, likely driven by endogenous Δ9 desaturase activity, followed by a later increase in polyunsaturated FAs attributable to exogenous dietary assimilation and/or mobilization from fat reserves. These findings identify UFA/SFA ratio as a strong correlate of cold tolerance in <em>D. lummei</em> and highlight the combined roles of endogenous metabolism and diet in membrane adaptation to cold.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"139 ","pages":"Article 104519"},"PeriodicalIF":3.2,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148318000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}